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arXiv · 1112.6051

1/(N-1) expansion for a finite U Anderson model away from half-filling

Akira Oguri
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Abstract

We apply recently developed 1/(N-1) expansion to a particle-hole asymmetric SU(N) Anderson model with finite Coulomb interaction U. To leading order in 1/(N-1) it describes the Hartree-Fock random phase approximation (HF-RPA), and the higher-order corrections describe systematically the fluctuations beyond the HF-RPA. We show that the next-leading order results of the renormalized parameters for the local Fermi-liquid state agree closely with the numerical renormalization group results at N=4. It ensures the reliability of the next-leading order results for N>4, and we examine the N dependence of the local Fermi-liquid parameters. Our expansion scheme uses the standard Feynman diagrams, and has wide potential applications.

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Akira Oguri. 2012-03-15. 1/(N-1) expansion for a finite U Anderson model away from half-filling. https://doi.org/10.1103/physrevb.85.155404

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